This is a linked open data (LOD) about date and time. "C.E. 0001 January 03" is a date of Julian Calendar (Calendar ID: 102.1).
http://datetime.hutime.org/calendar/102.1/date/C.E._0001_January_03
hcal:102.1/date/1721425.5
hcal:102.1/date/C.E._0001_January_03
hcaldate:1721425.5
hcaldate:C.E._0001_January_03